Exam 12: Solids: Structures and Applications

According to band theory, when the lower energy ________ band is separated from the higher energy ________ band by a large band gap, the material will act as a ________ of electricity.

If a body-centered cubic unit cell has a volume of 1.447 *10⁸ pm³, what must be the dimension of the cube's edge in picometers?

The sheet structure of carbon is ________

Gold has a face-centered cubic structure with a unit cell edge length of 407.8 pm. What is the contribution to the density from each individual gold atom in g/cm³?

Why are ceramic superconductors not currently practical for widespread transmission of electricity? I.They are relatively expensive in comparison to metals. II.They require extremely cold temperatures. III.They are brittle and lack ductility.

Which of these is the best conductor of electricity?

Which of the following unit cells has the lowest packing efficiency?

Which of the following unit cells has the highest packing efficiency?

The XRD scan of the face-centered cubic (fcc) structure of sodium chloride showed that there was a distance of 562.8 pm between "layers of ions." Given that the fcc unit cell has a volume of 178.26 *10^-24 cm³, to which distance does the 562.8 pm correspond?

Firing of a kaolinite clay object to make a ceramic results in ________

The alpha form of polonium (Po) has a density of 9.196 g/cm³ and crystallizes in a simple cubic structure. What is the atomic radius of polonium?

An approximately spherical allotrope of carbon containing 60 or 70 atoms is ________

In ionic solids, one ion often occupies a hole in the unit cell defined by the other ion. In a body-centered cubic cell, what are the types and numbers of each hole?

Iron (Fe) crystallizes as a body-centered unit cell with an edge length of 287 pm. What is the atomic radius of iron?

Consider the three unit cells below for ionic solids. In each unit cell, one of the ions is arranged in one of the standard unit cell structures while the other is found between these sites. What are the names of the minerals associated with each of these structures? I ________; II ________; III ________. I II III In addition to the ions There are 14 large and There are 14 small and shown, there is another 4 small ions depicted. 8 large ions depicted. at the very center of the unit cell.

Which element would be used to dope silicon to produce a p-type semiconductor?

The closest packing of spheres (such as oranges, cannonballs, or atoms) has the spheres ________

In the solid-state structure of sodium chloride, the closest distance between the centers of ions is observed ________

A hexagonal closest-packed structure has hexagonally arranged layers of atoms stacking in the series ________

Iron crystallizes in a body-centered cubic pattern. How many iron atoms are in each unit cell?